Single strands of deoxyribo- ("DNA") or ribo-("RNA") nucleic acid, formed from nucleotides including the bases adenine (A), cytosine (C), thymidine (T), guanine (G), uracil (U), or inosine (I), may hybridize to form a double-stranded structure held together by hydrogen bonds between pairs of complementary bases. Generally, A is hydrogen bonded to T or U, while G or I are hydrogen bonded to C. Along the chain, classical base pairs AT or AU, TA or UA, GC, or CG are present. Additionally, some mismatched base pairs (e.g., AG, GU) may be present.
Bringing together two single strands of nucleic acid containing sufficient contiguous complementary bases, under conditions which promote their hybridization, results in double-stranded nucleic acid. Under appropriate conditions, DNA/DNA, RNA/DNA, or RNA/RNA hybrids can form.
Background descriptions of the use of nucleic acid hybridization to detect particular nucleic acid sequences are given in Kohne, U.S. Pat. No. 4,851,330 issued Jul. 25, 1989, and by Hogan et al., International Patent Application No. PCT/US87/03009, entitled "Nucleic Acid Probes for Detection and/or Quantitation of Non-Vital organisms," both references hereby incorporated by reference herein. Hogan et al., supra, describe methods for determining the presence of a non-viral organism or a group of non-vital organisms in a sample (e.g., sputum, urine, blood and tissue sections, food, soil and water).
Mycoplasma pneumoniae is a prokaryote in the taxonomic Mollicutes class. Mollicutes lack a bacterial cell wall and have a small genome size. They are considered some of the smallest of the free-living microorganisms. Mycoplasma pneumoniae is a primary pathogen of man that produces acute respiratory disease. It is the most common cause of atypical pneumonia and is responsible for 15-20% of all pneumonia cases.
DNA hybridization assay probes directed to genomic sequences for detecting Mycoplasma pneumoniae are mentioned by Hyman et al., J. Clin. Microbiol. 25:726-728 (1987), Buck et al., J. Clin. Microbiol. 30:3280-3283 (1992), and Bernet et al., J. Clin. Microbiol. 27:2492-2495 (1989). Probes directed to ribosomal RNA (rRNA) sequences of Mycoplasma pneumoniae are mentioned by Tilton (Diagn. Microbiol. Infec. Dis. 10:109-112 (1988), Yogev et al., J. Clin. Microbiol. 26:1198-1201, (1988), Gobel et al., J. Gen Microbiol. 133:1969-1974, (1987), Hogan et al., Supra, Zivin and Monahah, EPO 305145, Application No. 88307793.5, and Gobel and Stanbridge, EPO 250662, Application No. 86304919.3. Kai et al., J. Med. Microbiol. 38:166-170, (1993), van Kuppeveld et al., Applied and Envir. Microbiol. 58:2606-2615, (1992), van Kuppeveld et al., Applied and Envir. Microbiol. 59:655 (1993), and Jensen et al., APMIS 97:1046-1048 (1989), describe primers directed to 16S rRNA sequences of M. pneumoniae. Weisburg and Pelletier, EPO Application Number 92305126.2, Publication Number 0 576 743 A1 mention probes to Mycoplasma pneumoniae, or, optionally Mycoplasma pneumoniae and Mycoplasma genitalium, nucleic acid. None of the references mentioned herein are admitted to be prior art.